fixed some small regressions and moved endian functions to a separate module

source/app.d

@@ -66,6 +66,7 @@ int main(string[] args)
         result.helpWanted = true;
     }
 
+    if(result.helpWanted)
         printHelp(result.options);
 
     return 0;

source/bitmanip.d

@@ -1,7 +1,6 @@
 module bitmanip;
 
 private import std.traits : isUnsigned;
-private import std.bitmanip : nativeToLittleEndian, littleEndianToNative;
 
 UIntType rotateLeft(UIntType)(in UIntType val, in size_t len) nothrow @nogc pure @safe
     if(isUnsigned!UIntType)
@@ -36,26 +35,3 @@ unittest
     assert(test[2].rotateRight(1) == 64);
     assert(test[2].rotateRight(7) == 1);
 }
-
-alias littleEndianInv = nativeToLittleEndian;
-
-uint littleEndian(in ubyte[] input) @safe pure nothrow @nogc
-in
-{
-    assert(input.length == uint.sizeof);
-}
-body
-{
-    ubyte[uint.sizeof] buf = input;
-    return littleEndianToNative!uint(buf);
-}
-
-unittest
-{
-    ubyte[] test0 = [0, 0, 0, 0];
-    ubyte[] test1 = [86, 75, 30, 9];
-    ubyte[] test2 = [255, 255, 255, 250];
-    assert(littleEndian(test0) == 0x00000000);
-    assert(littleEndian(test1) == 0x091e4b56);
-    assert(littleEndian(test2) == 0xfaffffff);
-}

source/chacha20.d

@@ -2,10 +2,10 @@ module chacha20;
 
 private import std.string : format;
 private import std.range : isInputRange, isForwardRange, ElementType;
-private import std.bitmanip : nativeToLittleEndian, littleEndianToNative;
 private import std.array;
 
 private import bitmanip;
+private import endian;
 
 public:
 

source/endian.d

@@ -0,0 +1,24 @@
+private import std.bitmanip : nativeToLittleEndian, littleEndianToNative;
+
+alias littleEndianInv = nativeToLittleEndian;
+
+uint littleEndian(in ubyte[] input) @safe pure nothrow @nogc
+in
+{
+    assert(input.length == uint.sizeof);
+}
+body
+{
+    ubyte[uint.sizeof] buf = input;
+    return littleEndianToNative!uint(buf);
+}
+
+unittest
+{
+    ubyte[] test0 = [0, 0, 0, 0];
+    ubyte[] test1 = [86, 75, 30, 9];
+    ubyte[] test2 = [255, 255, 255, 250];
+    assert(littleEndian(test0) == 0x00000000);
+    assert(littleEndian(test1) == 0x091e4b56);
+    assert(littleEndian(test2) == 0xfaffffff);
+}

source/salsa20.d

@@ -1,11 +1,11 @@
 module salsa20;
 
-private import std.traits : isUnsigned;
 private import std.string : format;
 private import std.range : isInputRange, isForwardRange, ElementType;
 private import std.array;
 
 private import bitmanip;
+private import endian;
 
 public: